OP, just saw your post on the other thread 
That's definitely the hyaluronic serum I use. I'm currently in Majorca in the middle of a heatwave, and my skin has not dried out at all. It's remarkably plump and glowy, which is a miracle for me, please believe me!
I just love it so much.
My routine is very much personalised for my oily, yet dehydrated skin. Prone to rosacea/acne flare ups - and the bane of my life.
I cleanse using cetaphil. After a long day, I can feel whiteheads/tightness/tingly rosacea flaring up - take your pick! This calms and cleanses. The relief as I slap it on, is immense. I double cleanse using this, or sometimes use olive oil/coconut oil.
I then use my nip and fab glycolic pads every night. They smooth and soothe. They do not irritate my skin at all using daily, even the extreme glycolic pads.
Next, I apply the hyaluronic serum (Hada labo). I have tried the Ordinary's one, it was ok, just less of it in the bottle and a bit too sticky.
I also like cosrx snail essence, as this soothes, especially at the end of the day.
Sometimes I layer them together. 
I then moisturise with the Ordinary's moisturiser, clinique dramatically different moisturiser or none at all. Using the serums has reduced my need for them tbh.
I may apply a drop of the Ordinary's squalene oil, it leaves the skin velvety smooth.
I then apply the 2% retinoid on top as the last step. I use it like this, as my skin can react if it's being a bit troublesome. This way ensures that no irritation happens. The serum/moisturiser/oils all act as a buffer.
The retinoid still has an effect, especially on my pores, smoothness and reduced redness. My skin is also ultra smooth, even with no thick, greasy creams used.
If my skin is very dry I may use Mizon's snail recovery gel cream. This leaves my skin so glowy and plump, without blocking those dreaded pores.
I also love the Hada labo sheet masks. Used after cleansing and the hyaluronic serum - leaves you with babysoft skin.
So soft, I cannot stop stroking it.
Sorry for the long post! Hope it helped (and didn't confuse you). 